1. Field of the Invention
The invention relates to a leak test method of detecting a leak in an engine, and relates also to a leak test apparatus configured to detect a leak in an engine.
2. Description of Related Art
There is a known leak test method of detecting a leak in an engine including camshafts rotatably disposed, a crankshaft coupled to the camshafts and rotatably disposed, and a plurality of cylinders each of which is provided with an intake valve and an exhaust valve that are driven by the camshafts and each of which includes a combustion chamber defined by a piston driven by the crankshaft and a cylinder wall (refer to Japanese Patent Application Publication No. 10-153518 (JP 10-153518 A)). In order to supply the fluid that have been introduced to the intake and exhaust ports into the combustion chambers of all the cylinders, the intake and exhaust camshafts that are not coupled to the crankshaft are rotated to open the intake or exhaust valve of each of all the cylinders. In this way, the fluid is supplied to the combustion chambers of all the cylinders.
In the above-described leak test, in order to fill the combustion chambers of all the cylinders with the fluid (e.g. air), the camshafts are rotated to open and close the intake or exhaust valve of the combustion chamber of each of all the cylinders. Thus, it takes a long time before the leak test is started. In particular, it takes a lot of time to fill the combustion chambers having a large inner volume with the fluid. Thus, a higher priority needs to be given to a supply of the fluid to the combustion chambers having a large inner volume.